Vacuum chuck for container closure lining machinery



July 3, 1969 w. B, HARRISON ET AL VACUUM CHUCK FOR CONTAINER CLOSURE LINING MACHINERY Fil ed Oct. 6; 1965 FIG.2

INVENTORS WILLIAM B.HARRISON RKJHARD C.BOULTOVN United States Patent Office 3,454,282 Patented July 8, 1969 3,454,282 VACUUM CHUCK FOR CONTAINER CLOSURE LINING MACHINERY William B. Harrison, Dedham, and Richard C. Boulton,

Waltham, Mass., assignors to W. R. Grace & 'Co., Cambridge, Mass., a corporation of Connecticut Filed Oct. 6, 1965, Ser. No. 493,465 Int. Cl. B23b 31/30; Bc 11/14; B25b 11/00 US. Cl. 2793 4 Claims ABSTRACT OF THE DISCLOSURE A chuck for crown closure lining machines adapted to position unbalanced tab type crown shells properly which includes a peripheral rim on the chuck, a centrally located pin to prevent tilting of the crown, and uniform spacing of air passages around the pin, thus maintaining the crown shell level during the lining operation.

This invention relates to vacuum chucks used in closure lining machines and particularly to a vacuum chuck designed to line bottle crowns.

Bottle crowns are sealed by means of a gasket which is interposed between the metallic crown and the mouth part of the bottle. Quite commonly the material from which the gasket is made is applied to the crown in a liquid form which later, either by heating or by drying, is consolidated into a solid gasketing substance. The lining operation is accomplished by centering the crown on a rotating chuck and then injecting a measured quantity of fluid lining composition into the crown.

To hold the crown on the chuck while it is rapidly rotating, a pressure differential is established by a so-called vacuum chuck. In the past, these chucks have been provided with a flat face at the periphery and a counterbore in the remaining area of the chuck face. The floor of the counterbore has often been tapered and leads to an axial bore extending through the chuck which, through rotary joints, connects to an air-displacement device.

Crown lining machinery runs at very high speeds. Often a single lining head will produce 300 crowns a minute. If any misfeeding occurs, time and material losses become very substantial.

The chucks which have previously been described work well with crowns of conventional design, but with the advent of the so-called tab-cap or the baseball cap, which includes a flap extending radially outwardly from one side of the crown and now used on many soft-drink and beer containers, the unsymmetrical nature of the cap causes tilting unsymmetrical lining, and misfeeding.

The chuck of the present invention permits all types of crowns whether conventional, tab, or baseball crowns to be run on the same machine and substantially eliminates the tilting, jamming, and misfeeding of tab and baseball crowns which occur when chucks of conventional design are used.

The essential features of the new chuck design include a peripheral edge support for the crown and a central pin which prevents any tilting of the cap from occurring whether the cap is being pushed on to or pushed away from the chuck by the feeding mechanism. The invention may best be understood by reference to the drawing, in which FIG. 1 is a top plan view of the improved chuck,

FIG. 2 is a vertical section on the line 22 of FIG.l, and

FIG. 3 is a detail sectional view of a knife edge formed at the chuck periphery.

Specifically, the chuck 10 comprises a cylindrical body 11 which extends upwardly from its lower end 13 to a point approximately A of an inch above the shoulder 14. Body 11 is shouldered at 14 as shown, to receive a removable ring 15, formed from a suitable metal such as carbide or all tool steel, which is cemented to the body 11. Spaced counterbores 16 drilled inwardly from the face of the body and so placed that their centers lie on a concentric circle, intersect and open into bore 12. A central pin 17 of the body 11 is supported by the webs 18 which extend between the counterbores 16, and projects upwardly from the face 19 to a point about 0.015 inch below the rim of the ring 15. The tip of the pin may be flat or provided with radii, but preferably it is convex or domeshaped, to support a crown in movement to and from the chuck.

The upper margin of ring 15 is preferably finished as shown in FIG. 3 to produce a sharp and carefully stoned edge. Its inner face descends at an angle of approximately 30 to the vertical; its outer face, for a distance of about 0.030 to 0.035 inch below the upper margin lies at an inward angle of 15 to the vertical. While a ring with a knife edge is preferred, satisfactory placement of crowns on the chuck is achieved with rings having a flat or radius surface.

The function of a carbide ring is solely to increase the service life of the chuck. Obviously, with some loss of service life, the chuck could be unitary and a knife-edge could be formed on the body 11.

The lower portion of the body 11 is externally threaded at 21 to allow the chuck to be screwed into the hollow rotating drive shaft of a lining machine (not shown).

The presence of the sharp knife-edge 22 permits a cap, even if it is domed, to seat on the chuck so that a proper pressure differential is maintained. This, together with the action of the pin 17, prevents the crown from seating at a tilt angle.

Further, the presence of the pin prevents any cap which is inherently unstable, such as the cap 23 having a lifting tab 24 as shown in FIG. 2, from tilting or sliding downwards into the counterbore as the cap is moved from the chuck. As a consequence, this chuck can, without any machine adjustments, except those nozzle adjustments required to control the volume and placement of the lining, handle all types of caps which now appear on the market. The occurrence of misfeeds and jams due to the unbalanced nature of the tab and baseball type caps is substantially eliminated.

We claim:

1. A vacuum chuck adapted for use in container closure lining machinery which machinery possesses a hollow rotatable chuck spindle connected to air-displacement means, said chuck comprising (a) a body having an upper end-face formed into a peripheral edge projecting upwardly therefrom,

(b) a pin centrally located with respect to the margin of said peripheral edge and terminating slightly below the vertical extent of said edge,

(c) a plurality of counterbores formed in said upper end-face between said edge and said pin,

3 4 (d) an axial bore extending from an opening in the 4. A chuck according to claim 1 wherein the face of the opposite end of said body to a point of intersection pin has a convex surface. with all of said plurality of counter-bores thereby forming an air passage through said body, and References Cited (e) means adjacent the lower end of said chuck to 5 UNITED STATES PATENTS permit its attachment to a rotatable spindle of a 1 2444531 7/1948 Richardson sure lining machine.

2. A chuck according to claim 1 wherein the upper end- ROBERT RIORDAN, Primary Examiner face is formed of a removable ring.

3. A chuck according to claim 1 wherein the peripheral 10 US. Cl. margin of the upper end-face is provided with a knife edge. 5 

